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Solstus: Solar Source Thermal Upper Stage, Don Jones Aug 1994

Solstus: Solar Source Thermal Upper Stage, Don Jones

Small Satellite Conference

During the past academic year the members of Utah State University's Space Systems Design class have worked on the design of SolSTUS (Solar Source Thermal Upper Stage), a solar propulsion system that could be carried into low earth orbit by small launch vehicles and still carry useful payloads into higher energy orbits or interplanetary missions. To demonstrate the capabilities of the SolSTUS the class worked to meet the requirements of a specific design reference mission. The reference mission was a lunar mapping and science mission launched from a Taurus launch vehicle. Several aspects of the solar thermal propulsion concept were …

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Isat-1 Communication System, Minghua Lu, Keshi Chen Aug 1994

Isat-1 Communication System, Minghua Lu, Keshi Chen

Small Satellite Conference

The communication system of the Iowa satellite ISAT-1 provides contact links between the satellite, the ground station, and a moderate number of remote ground data collection systems through the operation of two functional units. In this system, data is transferred over four VHF/UHF channels, each with a bandwidth of 15 KHz, at the rate of 9,600 bps per channel. The continuous phase binary frequency shift keying (CP-BFSK) is used for digital modulation/demodulation in the attempt to achieve a transmission error bit rate of 10(-6) or lower under the constraint of a very limited financial and power budget. Also, a command-driven …

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The Design And Construction Of The Stanford Audio Phonic Photographic Infrared Experiment (Sapphire) Satellite, Christopher Kitts, William Kim Aug 1994

The Design And Construction Of The Stanford Audio Phonic Photographic Infrared Experiment (Sapphire) Satellite, Christopher Kitts, William Kim

Small Satellite Conference

The students of Stanford University's Satellite Systems Development Laboratory (SSDL) have commenced detailed design and construction of a new micro satellite. Named the Stanford Audio Phonic Photographic Infrared Experiment (SAPPHIRE), this spacecraft's payloads include a miniature infrared (IR) research package, a digital camera, and a voice synthesizer. The bus consists of a 25 pound, 9 inch tall, 16 inch diameter hexagonal structure with complete processor, communication, power, thermal, and attitude control subsystems. The SAPPHIRE spacecraft is the first vehicle of the SSDL's new Satellite Quick Research Testbed (SQUIRT) program. The goal of this project is to produce student engineered satellites …

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Miniaturization Methods For Deep Space Microspacecraft, Lilac Muller Aug 1994

Miniaturization Methods For Deep Space Microspacecraft, Lilac Muller

Small Satellite Conference

Due to the shrinking NASA budget, future scientific spacecraft programs will be driven by their "life-cycle" cost. This cost figure, which includes development integration, launch, and operation, can be reduced by making spacecraft smaller and more autonomous. Such miniature spacecraft allow the launch of several microspacecraft on a single launch vehicle or the launch of a single microspacecraft as a "piggy-back" rider on top a primary payload. Although each of these small spacecraft will not be capable of conducting the diversified science that is accomplished by such grand vehicles as Voyager and Cassini, a group of microspacecraft can conduct a …

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Design Of The Isat-1 Satellite Thermal Control System, Joseph Clay Aug 1994

Design Of The Isat-1 Satellite Thermal Control System, Joseph Clay

Small Satellite Conference

Satellite technology improves the daily lives of almost all human beings. Satellites aid in communication, weather prediction, and global positioning. Other uses for satellites include conducting scientific experiments in micro gravity and space exploration missions. A major constraint placed on all satellites is the cost of launch. With a larger or heavier satellite, a larger more powerful launch vehicle is need. This larger launch vehicle increases the overall satellite cost. The development of smaller satellites promises lower cost by relaxing the launch vehicle cost constraint. Smaller and lighter satellites are less expensive to launch, and are expected to provide a …

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A Microparticle Recognition Experiment For Near-Earth Space On Board The Satellite Asusat 1, Charles Hewett Aug 1994

A Microparticle Recognition Experiment For Near-Earth Space On Board The Satellite Asusat 1, Charles Hewett

Small Satellite Conference

The Microparticle Recognition Experiment (MRE) under development for flight on the ASUSat 1 mission to measure the flux, mass, velocity, trajectory and temperature of near-Earth microparticles is discussed. A parabolic PVDF copolymer array sensor with particulate position detection capabilities is employed to distinguish between natural particles and orbital debris in low-Earth orbit. Measurements will cover the particle mass range ~ 2 x 10 -12 g (2 µm diameter) to ~ 1 x 10 -2 g (1mm diameter) with an expected mean error in particle trajectory ± 7 degrees. ASUSat 1 is a 10 LB class microsatellite under design and development …

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Preliminary Design Of Asusat 1, Joel Rademacher Aug 1994

Preliminary Design Of Asusat 1, Joel Rademacher

Small Satellite Conference

ASUSat 1 represents a revolution in space science. The project will be smaller, faster, and cheaper than most comparative missions. The students at Arizona State University are challenged to design, fabricate, and launch a 10-pound-class (4.5 kg) satellite to perform meaningful science in space. Orbital Sciences Corporation is developing the deployment system for this prototype payload from the Pegasus launch vehicle. The project will allow for low-cost measurement of micro particles from interplanetary dust and asteroids in low Earth orbit. The satellite will be placed in a near-polar, sun-synchronous orbit to detect the flux, mass, velocity, trajectory, and temperature of …

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The Satellite Quick Research Testbed (Squirt) Program, Christopher Kitts, Robert Twiggs Aug 1994

The Satellite Quick Research Testbed (Squirt) Program, Christopher Kitts, Robert Twiggs

Small Satellite Conference

Stanford University's Department of Aeronautics and Astronautics has commenced full scale development of a new micro satellite initiative. Known as the Satellite Quick Research Testbed (SQUIRT) program, the project's goal is to produce student engineered satellites capable of servicing state-of-the-art research payloads on a yearly basis. This program is specifically designed to meet the education and research goals of the department's Satellite Systems Development Laboratory. The first spacecraft in the SQUIRT series is the Stanford Audio Phonic Photographic Infrared Experiment (SAPPHIRE). The payloads for this mission include an experimental infrared (IR) sensor, a digital camera, and a voice synthesizer. The …

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Lessons Learned From Clementine On The Way To Pluto, J. Carraway, P. Henry, M. Herman, G. Kissel, H. Price, R. Staehle, M. Underwood Aug 1994

Lessons Learned From Clementine On The Way To Pluto, J. Carraway, P. Henry, M. Herman, G. Kissel, H. Price, R. Staehle, M. Underwood

Small Satellite Conference

Clementine has demonstrated a variety of hardware, system design, and operations innovations. The Pluto design team is currently evaluating the applicability of many Clementine approaches for the Pluto Flyby mission, including: 1) A focused science instrument payload exploiting low mass, low power instruments. 2) Using Clementine star cameras. 3) A similar flight computer architecture exploiting separate, dedicated spacecraft and instrument computers. 4) Using the same high order uplink programming / control language (SCL - "Spacecraft Command Language") 5) A similar operations style and organization during cruise. At the same time, differences in the Pluto mission, lifetime, reliability, trajectory, and data …

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Msti-3 Commander-In-The-Field "Battlefield" Payload Command Demonstration, Todd Probert, Dale Lockwood Aug 1994

Msti-3 Commander-In-The-Field "Battlefield" Payload Command Demonstration, Todd Probert, Dale Lockwood

Small Satellite Conference

The Ballistic Missile Defense Organization's (BMDO) Miniature Sensor Technology Integration (MSTI) program is conducting research and development into advanced satellite command control architectures, including options for theater command and control by U.S. forces. Elements within the National Test Facility (NTF), Falcon AFB, CO, will use MSTI satellites as prototype test assets to develop and evaluate potential satellite command and control systems to improve future satellite control architectures and on-orbit satellite operations. The overall MSTI Concept of Operations centers around a mission control segment that is interoperable and capable of supporting multiple missions within a single core architecture. The ground segment …

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The In-Orbit Operation Of Four Microsat Spacecraft--Four Years Later, Robert Diersing Aug 1994

The In-Orbit Operation Of Four Microsat Spacecraft--Four Years Later, Robert Diersing

Small Satellite Conference

More than four and one half years have passed since the launch of four Microsat spacecraft developed by the Radio Amateur Satellite Corporation of North America (AMSAT-NA) and other cooperating AMSAT groups. This paper documents the current status of the four Microsats with particular emphasis on AO-16 and DO-17. The software supporting the store-and-forward message system of AO-16 and LO-19 has changed significantly since launch, starting out as a real-time digital repeater, progressing to a connected-mode file server, and finally evolving to a broadcast-mode file server. A concise description of this software evolution is included along with long-term satellite usage …

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Msti-3 Science Objectives, William Jeffrey, James Fraser, Maj. Garret Schneider Aug 1994

Msti-3 Science Objectives, William Jeffrey, James Fraser, Maj. Garret Schneider

Small Satellite Conference

MSTI-3 is a Ballistic Missile Defense Organization (BMDO) experiment to be launched on a Pegasus booster in the winter of 1994/1995. It is the first of the MSTI satellites with the primary objectives being science-driven and is a good example of the science which can be done from a small satellite in low earth orbit. A Science Working Group has been organized to define the payload requirements and to set the observation plans. Provided here is an overview of the science objectives which include SWIR and MWIR background clutter characterization; monocular and stereo track of boosting and nonboosting targets; environmental …

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The Zipsim Series Of High Performance, High Fidelity Spacecraft Simulators, W.K. Reinholtz, W.J. Robison Aug 1994

The Zipsim Series Of High Performance, High Fidelity Spacecraft Simulators, W.K. Reinholtz, W.J. Robison

Small Satellite Conference

This paper describes the architecture and applications of the ZIPSIM series of spacecraft simulators. ZIPSIM is the foundation upon which spacecraft simulators are built at either the register-transfer level or lower level of fidelity. A simulator for a particular spacecraft is built by combining mission-specific components with standard ZIPSIM components. ZIPSIM provides standardized capabilities including utilization of multi-processor hosts, common components (e.g. schedulers, graphical and command-line interfaces, and data displays), reusable models (e.g. processors such as MIL-STD-1750A), uplink and telemetry interfaces related to Mission Operations at JPL, standards for runtime establishment and operation of component interconnections, and a standard command …

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Dependability Design For The Pluto Flyby Mission, Stephen Johnson, Larry Cooper, Don Uhrich Aug 1994

Dependability Design For The Pluto Flyby Mission, Stephen Johnson, Larry Cooper, Don Uhrich

Small Satellite Conference

The Pluto Flyby mission poses very stringent dependability requirements. These requirements drive a design that must optimize the reliability of the system over a decade, the availability of the spacecraft during the crucial flyby period, and the security of the science data during the long post-encounter playback period. This paper discusses the initial studies of the processes and techniques which will be used for the dependability of this difficult mission. These studies and initial analyses draw from dependability research and development at various institutions over the last two decades. After briefly outlining the major features of this prior work, their …

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A Cost Model For A University Satellite Program, Emery Reeves Aug 1994

A Cost Model For A University Satellite Program, Emery Reeves

Small Satellite Conference

A number of universities are involved in designing small satellites for research or for educational projects. The amateur radio community is also engaged in similar projects. Study of the economic basis for these projects shows a number of common elements such as the number of people involved, degree of dedication, use of available hardware, and schedule span times. This paper is an attempt to summarize this experience and formulate a common economic model as an aid to planning future projects and examining process characteristics of such programs.

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A New Approach To Flight Equipment: Clementine & Msti Work At Jpl, Kenneth Hicks, James Wall Aug 1994

A New Approach To Flight Equipment: Clementine & Msti Work At Jpl, Kenneth Hicks, James Wall

Small Satellite Conference

The Ballistic Missile Defense Office/Air Force's Clementine and Miniature Seeker Technology Insertion (MSTI) programs have set new standards for spacecraft cost/performance. At the Jet Propulsion Laboratory, work on these programs has driven changes in traditional approaches to spacecraft design, fabrication, test and integration. High-visibility, billion-dollar spacecraft are typically built to a "Class A" standard of quality and reliability. Organizations, including JPL, which receive multiple development contracts for Class A missions have been very successful in creating approaches which do a good job of delivering to these high standards. They have been less successful, however, in modifying these standards for programs …

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One Year In Space: Results From Posat-1, Maarten Meerman, Martin Sweeting, Miguel Leitmann Aug 1994

One Year In Space: Results From Posat-1, Maarten Meerman, Martin Sweeting, Miguel Leitmann

Small Satellite Conference

PoSAT-1 was launched in September 1993, joining the UoSAT family of spacecraft already in orbit. Built by Surrey Satellite Technology Ltd. (SSTL) for a consortium of Portuguese industry, PoSAT-1 represents the latest generation of UoSAT microsatellites. This paper will briefly review the development and evolution of the UoSAT design. It will then summarize key functional parameters of PoSAT-1 including attitude determination and control, electrical power, data handling systems, thermal control and communications. PoSAT-1 contains a variety of experiments including CCD wide and narrow field Earth imaging cameras, a star field sensor, a GPS receiver, cosmic radiation and total radiation dose …

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Miniature Sensor Technology Integration (Msti) Flight Test Results, David Erickson, Jason Feig, Ed Grigsby, Alan Carlson Aug 1994

Miniature Sensor Technology Integration (Msti) Flight Test Results, David Erickson, Jason Feig, Ed Grigsby, Alan Carlson

Small Satellite Conference

The MSTI-2 satellite mission is the second in a series established to test, in realistic scenarios, miniature spacecraft and sensor technologies for missile detection and tracking on low cost, low-earth orbit technology demonstration satellites. Cooperative demonstrations are planned to combine MSTI-provided target track file information, with interceptor technology tests, to fully demonstrate technologies associated with theater missile defense (TMO) targeting. The program is sponsored by the Ballistic Missile Defense Organization (BMDO) and executed by a government/industry team led by the Air Force Phillips Laboratory's Space Experiments Directorate (operating location Edwards Air Force Base). The MSTI-2 mission will demonstrate several advanced …

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Electronic Trap Microscopy - A New Mode For Scanning Electron Microscopy (Sem), H. -J. Fitting, Th. Hingst, R. Franz, E. Schreiber Aug 1994

Electronic Trap Microscopy - A New Mode For Scanning Electron Microscopy (Sem), H. -J. Fitting, Th. Hingst, R. Franz, E. Schreiber

Scanning Microscopy

Insulating layers on conducting substrate are investigated by means of secondary electron field emission SEFE in a digital SEM. The kinetics of charge storage and release with time and temperature are controlled and recorded by an external computer.The evaluation is performed pixel-wise with respect to electronic trap concentration nt0, trap capture cross section σc and thermal activation energy Et. Mapping of these trap parameters indicates hidden inhomogenities, defects and pre-treatments of the dielectric layers as well as the pattern of thermal bleaching and release of electrons. The latter ones appear as inhomogeneous processes starting with …

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General Pattern And Morphological Specializations Of The Avian Cochlea, Franz Peter Fischer Aug 1994

General Pattern And Morphological Specializations Of The Avian Cochlea, Franz Peter Fischer

Scanning Microscopy

In different bird species, there is a common pattern in the hair-cell morphology and innervation of the basilar papilla; the absolute values, however, are species-specific. In the barn-owl papilla, an extreme being case, the basal high-frequency part of the papilla is greatly expanded. In this behaviorally most important frequency range of the barn owl, the number of afferent nerve terminals to neural hair cells is extensively increased. Instead of about 2 afferent terminals as in other species, up to 20 afferents are present. In the bird species studied (chicken, starling, emu, barn owl), the area of the afferent nerve terminals …

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Time-Resolved Cryofixation Methods For The Study Of Dynamic Cellular Events By Electron Microscopy: A Review, Keith P. Ryan, Gerd Knoll Jul 1994

Time-Resolved Cryofixation Methods For The Study Of Dynamic Cellular Events By Electron Microscopy: A Review, Keith P. Ryan, Gerd Knoll

Scanning Microscopy

The preservation of cells for electron microscopy by chemical fixation is a lengthy process, requiring up to 30 minutes for cytoplasmic stabilisation. This time lag enables many changes to occur in specimens so that they may not reflect their living state when they are observed in electron microscopes. Many artefacts can be avoided by using cryofixation, which freezes specimens over a period that is measured in milliseconds, so that specimens are preserved by cryoimmobilisation. This time resolution can be used to study rapid processes in biology and chemistry because, although electron microscopes cannot observe dynamic cellular events directly, processes can …

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An X-Ray Microanalytical Study On The Effects Of Ouabain And N-Ethyl Maleimide On The Elemental Concentrations In Malpighian Tubule Cells Of Locusta, Natalia Pivovarova, John H. Anstee, Ken Bowler Jul 1994

An X-Ray Microanalytical Study On The Effects Of Ouabain And N-Ethyl Maleimide On The Elemental Concentrations In Malpighian Tubule Cells Of Locusta, Natalia Pivovarova, John H. Anstee, Ken Bowler

Scanning Microscopy

X-ray microanalysis was used to study elemental distribution in Malpighian tubule cells of Locusta migratoria and how these are affected by the replacement of bathing medium K+ with Rb+ and by inclusion of the transport inhibitors ouabain and n-ethyl maleimide (NEM) in standard (K+-containing) and Rb+-Ringer (K+-free) solutions. Incubation of tubules in standard Ringer containing 1 mM ouabain dramatically affected the intracellular levels of K and Na. The intracellular K concentration fell and Na concentration increased in all regions studied. Despite this, a gradient of increasing K concentration from basal to apical …

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Evaluation And Utilization Of Biodiversity In Triticeae For Wheat Lmprovement, A. B. Damania, J. Valkoun Jun 1994

Evaluation And Utilization Of Biodiversity In Triticeae For Wheat Lmprovement, A. B. Damania, J. Valkoun

Herbarium Publications

To adapt new varieties to a wide spectrum of environments breeders and farmers have emphasized the need for broadening the current narrow genetic base of modern varieties of important cereal crops such as wheat and barley. In response to this need, several thousand samples of indigenously cultivated Triticeae species and their wild relatives have been collected from the centers of diversity. However, gene bank collections are of little use if they are not evaluated and the information disseminated widely. Evaluation is essentially the link between conservation and use. Some of the collected material has been evaluated at the International Center …

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The Evaluation On Crossabilities Of Chinese Wheat Landraces, M. C. Luo, C. Yen, J. L. Yang, Z. L. Yang Jun 1994

The Evaluation On Crossabilities Of Chinese Wheat Landraces, M. C. Luo, C. Yen, J. L. Yang, Z. L. Yang

Herbarium Publications

The total of 865 accessions of Chinese bread wheat landraces (Triticum aestivum L.) has been investigated on their crossabilities with rye (Secale cereale L.), of which 121 land races showed similar crossability to Chinese Spring, 50 accessions had much higher crossability than Chinese Spring, and 693 varieties were non-crossable with rye or had lower crossability than Chinese Spring. The analysis on the geographical distribution indicated that the landraces with high crossability occurred in most parts of China. Some utilization of high crossability resources was also discussed.

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Diversity Of Trypsin Inhibitors In Cultural And Wild Barley, Ladogina M. P., Ovchinnikov A. N., Fetisov A. V. Jun 1994

Diversity Of Trypsin Inhibitors In Cultural And Wild Barley, Ladogina M. P., Ovchinnikov A. N., Fetisov A. V.

Herbarium Publications

Diversity of trypsin inhibitors was studied in 35 spring barley cultivars (Hordeum vulgare), 21 samples of H. spontaneum, and 3 samples of H. agriocrithon. Six variants of trypsin inhibitor spectra were identified by native electrophoresis method followed by specific development of activity. Four variants were found in both cultivated and wild barley, and the other two were revealed only in H. spontaneum. Trypsin inhibitor activities (TIA) and soluble protein contents were determined in four cultivars with different variants of trypsin inhibitors. It was shown that TIA differed in the cultivars studied and did not correlate …

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Plant Germplasm Resources, S. A. Eberhart, H. E. Bockelman Jun 1994

Plant Germplasm Resources, S. A. Eberhart, H. E. Bockelman

Herbarium Publications

Landraces and wild relatives of crops from centers of diversity have been rich sources of resistance to new pathogens, insect pests, and other stresses as well as for traits to improve food and fiber quality, animal feed, and industrial products. Because very few crops grown in the U.S. are native, plant introductions are vital to our agriculture. The National Plant Germplasm System (NPGS) was established to acquire, preserve, and distribute plant genetic resources from around the world so that scientists have immediate access to these source materials. The active collection is maintained and distributed by 19 national germplasm repositories. The …

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Influence Of A Corpus Luteum Tissue Extract On Rabbit Ovarian Mesothelial Cells, S. V. Nicosia, R. J. Narconis, B. O. Saunders Jun 1994

Influence Of A Corpus Luteum Tissue Extract On Rabbit Ovarian Mesothelial Cells, S. V. Nicosia, R. J. Narconis, B. O. Saunders

Scanning Microscopy

This study investigates rabbit ovarian mesothelial (OM) cells exposed in vitro to a crude corpus luteum extract (CLE; 60 μg/ml). The growth of OM cells was evaluated by measuring the change in cell number (mean % ± standard error of mean, SEM), the number of cell population doublings (CPD ± SEM), and the cell population doubling time in hours (CPDT ± SEM) after 7.5 days of culture in a serum-poor medium. Quantitative estimates of surface morphology changes were obtained by analyzing the total number (mean no. ± SEM), density (mean no./100 μ.m2 ± SEM), and length-to-diameter ratio (mean L/D …

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Utah State University Commencement, 1994 – Main Campus, Utah State University Jun 1994

Utah State University Commencement, 1994 – Main Campus, Utah State University

Commencement Programs

101st Annual Commencement of Utah State University

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Effect Of Irrigation On Crabapple Growth And Water Relations During Field Production With In-Ground Fabric Containers, Roger Kjelgren, C. Spihlman, B. R. Cleveland Jun 1994

Effect Of Irrigation On Crabapple Growth And Water Relations During Field Production With In-Ground Fabric Containers, Roger Kjelgren, C. Spihlman, B. R. Cleveland

Plants, Soils, and Climate Faculty Publications

Growth and water relations of irrigated and non-irrigated Malus sieboldii var. zumi produced with and without in-ground fabric containers in a field-nursery setting were investigated. Predawn and midday leaf water potential and midday stomatal conductance were measured periodically through the season, and trunk increment, leaf area, root growth, and osmotic potential were measured in late season. Water potential became more negative and stomatal conductance decreased in non-irrigated treatments during an extended mid-summer drought that resulted in less trunk diameter gorwth and leaf area. Trees grwon in fabric-containers, both irrigated and non-irrigated, exhibited no detectable differences in water relations over the …

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Growth And Water Relations Of Kentucky Coffee Tree And Silver Maple Following Transplanting, Roger Kjelgren, Brenda Cleveland Jun 1994

Growth And Water Relations Of Kentucky Coffee Tree And Silver Maple Following Transplanting, Roger Kjelgren, Brenda Cleveland

Plants, Soils, and Climate Faculty Publications

Following transplanting we monitored growth and water relations over two years in Kentucky coffee tree (Gymnocladus dioica (L.) C. Koch) and silver maple (Acer saccharinum L.). Field-grown, well-established tress transplanted in place were compared to non-transplanted control trees. Predawn water potential was measured twice each month for two growing seasons, as well as midday stomatal conductance and water potential. Shoot elongation, leaf size, diameter growth, and total leaf area were determined both years. Less total leaf area as a result of transplanting apparently moderated total tree transpiration in both species. Reduced tree transpiration allowed stomatal conductance and predawn water potential …

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